Method of making angular tubing bends



June 13, 1933. F. M. KEPLER I METHOD OF MAKING ANGULAR TUBING BENDS Filed Oct. 10, 1930 2 Sheets-Sheet l zzvegi arr J 1 .71 fi'g zer. 5

June 13, 1933. j p, M, EPLER 1,913,490

METHOD OF MAKING ANGULAR TUBING BENDS 'Filed Oct. 10, 1930 2 Sheets-Sheet 2 Ulllllllllllllll! ll r WI enema a 13, 1933 use \ 'cIs 3.33am or crash. Danna, Pnunsmvmm IETEOD OI HAIING ANGULAB TUBING BEHDB Application fled October 10, 1930.. Serial in; mm;

relates to a method of bends of metallic tubing This invention producing angular and more particularly to the production of such bends in a manner providing the & bend with a true bore. While many attempts have been made to produce such bends, heretofore they have all depended u on some disgents at its ends Obvioulsly, a bend having no tangents is extremely d' cult to ada t for connection for it is ractically impossi le to properly thread sue a bend for the reception of a flan e or coupling.

My method consists briefly in employing a solid steel or wrought iron bar of the desired dimensions, drilling an axial pilot opening through this bar which is of such small size that it will not be materially distorted when the. bar is subsequently formed to the desired bend, then enlarging this opening by passing through the bar a cutter, or a series of cutters, for enlarging the pilot opening 85 to the desired dimensions, the single cutter when employed being guided by a pilot operating in the originally formed opening and the series of cutters bemgguided in the first instance by the pilot opening and for suc- 40 ce'eding cutters by the opening made by the preceding cutter.

The steps employed in producing an angular bend in accordance with my invention are semi-diagrammatically illustrated by the 46 accompanying drawings, in which:

Fig. 1 is a perspective view of the bar before bending and with the pilot opening formed therethrough;

Fig. 2 is a side elevation illustratin one of the several forms in which the bar is nt;

incapable of producinga bend having tan- Fig. 3 is a further form in which the bar ma be bent;

ig. 4 is a still further bent form;

Fig. 5 is a sectional view illustrating the enlargement of the opening by use of a rotating reamer pulled through the pilot opena Fig. 6 is a similar view illustrating the use of a reamer pushed through the opening; I

Fig. 7 is a view illustrating the use of one of a series of broaches to enlarge the opening; and

Figs. 8 and 9 are two others of the series of breaches necessary to enlargement of the pilot opening to its'proper size.

In these drawin s, forthe purpose of illustration of the pi 0t, bore enlargement the bend formed has been illustrated as an L havin tangents T. It will be understood that y employing the same procedure a .return bend such as illustrated in Fig. 3 or a pairof integrally connected spaced bends the connection between which is straight, as illustrated in Fig. 4, may be readily produced. I

Referring now more particularly to these drawings, the bar originally employed is indicated at 10 and the pilot opening drilled therethrough at 11. This openin is of such size that when the bend is pro need from the bar it will not be materially distorted that is to say, it will not be distorted beyondthe tolerance limits for a guide such as that hereinafter described.

After drilling of the opening, the bar is bent, this bending being accomplished in an suitable machine or fixture, following which the pilot opening is enlarged to the desired size. This is accomplished by any of the several mechanisms illustrated in the drawings.

In the form shown in Fig. 5 the numeral 12 designates a rotary reamer or cutter of a construction such that it will increase the size of the pilot opening from its normal size to the desired internal diameter for the bend. The forward end of this reamer has an axial, forwardly tapering projection 13 functioning as a pilot and having its greater diameter very slightly less than the diameter of the pilot opening 10. Connected with this In Fig. 6 this means constitutes a flexible" shaft 14a for rotating the 'org anizationhnd forcing the cutter through the bend guided by the engagement of the pilot in the pilot opening. As a means preventing flexing of the flexible shaft 14a as regards those portions thereof external to the bore which is being formed, a standard guiding sleeve is provided to surround such portions of the flexible shaft.

In Fig. 7 I have illustrated a means for enlarging the opening by a broaching operation. Where broaching is resorted to, due to the small size of the pilot opening as originally formed, use of a series of breaches IS necessary. The first broach is indicated at 16, this broach having a pilot 1'? to engage in the pilot opening 11 and be guided thereby, this broach enlarging the opening to an extent indicated at 1111. A. second broach 16a shown in Fig. 8 has a pilot 17a to fit the enlarged opening 11a formed by the breach 16, the pilot fitting the bore 11a while the third broach shown in Fig. 9 at 16?) has a ilot 17b to fit the enlarged opening 11?) proueed by the broach 16a. The series of broaches may contain any desired number, depending upon the character of the material acted upon and the differences in diameter between the pilot bore and the bore which is to be finally produced. Such broaches may be either pulled or pushed through the'*openings, the latter method of operation being herein illustrated.

In this construction as in the construction employing the cutters, a flexible movable member 141) must be employed for-moving the broaches through the bar. This flexible member. when pushed must, obviously, be guided by a sleeve 15a similar to the sleeve 15 to prevent deflection of those portions of the flexible member which are exterior to the opening being formed. It will be obvious that by following the method hereinbefore set forth it is possible to produce angular bends B of any desired character and having tangents of desired length, and provide such bends 'with bores of uniform diameter and curvature. Obviously, by these processes either flanged or unflangedbends may be produced.

As both the method and apparatus employed are capable of considerable modification, I do not wish to be understood as limiting myself to the specific examples herein ilven except as hereinafter claimed.

"bends" attesting d ll straight bar form ipg an axial pilot opening aeiaaee 1. The method of producing tubular angle bends consisting in employing a normally straight bar, forming an axial pilot opening of a diameter relatively small as regards the desired diameter of the final openin in the finished bend, shaping the bar to produce thedesieed bend anci passinge cutting means through the ban, tot inc-tease the div ameter of the opening.

pe 'oducing tubular angle 2. The method of hii'pioyi'ng a norma iy of adiameter relatively small as regards the desired diameteigofit e final opening in the finished bend, shaping he bar to produce the desired bend and passing a cutter through the bar to increase the size of the opening while employlng-the pilot opening as aguide for such cutting means.

3. The method of producing: tubular angle bends consisting.v in. employingfla normally straight bar, forminga longitudinal pilot opening therein of: a diameter relativelysmall as regards the desireddiameterjot the final opening in the finishe bend shaping the bar to produce a .5 bend includin alternate arcuate and tangentportionsan enlarging. the opening by passing a cutter therethrough.

4c. The methodof producing-angular bends of metallic tubing consisting informing the bend with an opening having alternate arcuate and tangent portions and of considerably less diameter than the diameter of the opening of the completed bend and then passing a cutter through the opening to enlarge said opening to a desired and uniform diameter while guiding the cuttertby. the opening.

5. The method of producing angular bends of metallic tubing. consisting in forming the bend with an opening comprising terminal arcuate portions, and an'intermediate tangent straight portion, the opening being-of considerably less d-ianieterithan the diameter of the opening of the completed bend and thenpassing a cutterthrough the opening to enlarge saidopeiiing to a desired and uniform diameter while guiding the cutter by the opening. i v

6. The method of .producing angular bends of metallic tubing cofisisting in forming the, bend with an opening comprising a central, arcuate portiona'nd terminal tangent por tions, the opening being-of considerably less diameter than the diameter of the opening of the completed bendand then passin a cutter through the opening to enlarge sai opening to the desired and uniforin'diameter while guiding the cutter by'the opening.

' FRANCIS M. KEPLER. 

